Telegraphy



2 Sheets-Sheet 1.

0. R. ROBERSON.

- TELEGRAPHY.

No. 583,418. A Patented May 25,1897.

WITNESSES: INVENTOR:

(No Model.) 2 Sheets-Sheet 2. O. R. ROBERSON. TELBGRAPHY.

No. 583,418. Patented'May 25,1897.

INVENTOR: (@Q

By his Affomey UNITED STATES PATENT, Orrrcn.

OLIVER R. ROBERSON, OF GLEN RIDGE, NElV JERSEY, ASSIGNOR TO THE IVESTERNUNION TELEGRAPH COMPANY, OF NENV YORK.

TELEGRAPHY.

SPECIFICATION forming part of Letters Patent No. 583,418, dated May 25,1897. Application filed August 24, 1896. Serial No. 603,682. (No model.)

To aZZ whom it may concern.-

Be it known that I, OLIVER R. ROBERSON, a citizen of the United Statesof America, residing at Glen Ridge, Essex county, and State of NewJersey, have made a new and useful Improvement in Diplex and QuadruplexTelegraphs, of which the following is a specification.

My invention relates to that class of telegraphs in which two messagesare simultaneously sent in one direction over a main line by means of arapid succession of positive and negative pulses. Others have heretoforeproposed the transmission of pulses in this order for the sending of twomessages; but in these cases the depressions of the keys have served tosuppress the positive and negative pulses, respectively. In other words,the positive pulses of the series are suppressed by operating one keyand the negative pulses by the other. In my systennhowever, one messageis transmitted by positive and the other by negative pulses, although,preferably, I send to line at all times a series of weak alternatingcurrents. On short lines signals may be transmitted by merely sending aseries of positive or negative pulses, according to the key depressed;but upon longer lines signals are sent by increasing one polarity or theother or both of currents normally flowing to line-that is to say, thepositive pulses are strengthened by depressing one key, while thenegative pulses are strengthened by the other. Thus with both keys atback contact only weak alternating pulses are sent to line, while uponthe depression of the keys strong positive or negative or strong pulsesof both polarities are transmitted as one or the other or both of thekeys are depressed. In this class of telegraphs others have suggestedbatteries and automatic vibrators for directing pulsatory currents uponthe line; but such devices have been found impracticable, owing to thelarge sparks produced at vibrating contacts and the inequality ofourrent-pulses produced. To avoid these difficulties and to secure otheradvantages hereinafter set forth, I employ at each station analternating-current dynamo provided with suitable collector-rings andconnections for sending to line positive and negative pulses for the twosets of signals and such further means as may be necessary for normallyfeeding weak alternating pulses into the main line and for directingthereto positive and negative currents of increased strength upon thedepression of one or the other or both of the two keys, as aboveoutlined. Again, in telegraphs employing rapidly-alternating currentsand relays responsive one to positive and the other to negative pulsesthe principal difficulty has been that a receiving-relay which shouldrespond to positive pulses only, or one which should respond alone tonegative pulses, is placed under essentiallydifferent conditions whencalled upon to act under the influence of a succession of pulses of bothpolarities, and it is to this difficulty that my invention is chieflydirected. Obviouslya relay should be subject to the same forces asnearly as possible at all times when called into action-that is to say,to attain the desired result a relay responsive to negative pulsesshould be equally responsive either when negative pulses only are sentover the line or when both positive and negative pulses are transmitted;also, a relay responsive to positive pulses should be equally responsiveeither to positive pulses alone or to asuccession of positive andnegative pulses. Either positive or negative pulses alone will producestrong electromagnetic effects; but in a rapid succession of alternatingcurrents the effect of any one current-wave is largely neutralized bythe pulse which follows.

My invention further consists in other and more specific means ofimprovement hereinafter set forth.

Figure 1 represents a current generator with transmitting and receivingapparatus at one station of my diplex or quadruplex systern. Fig. 2 is adiagram representing waves of positive pulses which are transmitted foractuating one relay at the receiving-station. Fig. 3 represents thewaves of negative pulses for actuating the second receiver at a station,while Fig. 4 represents both the waves of positive and negative pulsesfor simultaneously actuating both relays of a receivingstation. Fig. 5represents a relay-magnet which, according to the polarity of thehorseshoe magnet, is adapted to respond either to positive or negativepulses. Fig. 6 shows a modification of the receiving relay apparatusshown in Fig. 1, while Fig. 7 represents a bridge form of diplex insteadof the differential form of Fig. 1.

In Fig. 1 I have shown an alternating-current generator of the ring typewith its armature-coils a connected in two branches to a ring I),insulated from the shaft 6 of the dynamo, while the other terminal ofthe armature branch is connected to section 1 of hub c, the latter alsobeing placed upon the shaft 6. The hub c is provided with four metallicplates, upon the periphery of which rest two brushes connected,respectively, with conductors 11 and 13. As shown in the drawings, onearmattire-terminal is in contact with wire 11, while plate 3, which isinsulated from plate 1, is joined with branch 13. At the same timeplates 2 and 4:, which are insulated from 1 and 3, are connectedtogether by wire 8 with the hub b and thence to earth by wire 10. Also,upon shaft 6 is placed a hub cl, having sections 5 and 6, section 6being permanently connected by conductor 9 through hub Z) to earth,while section 5 affords an insulated terminal either for wires 12 or ll,according to its position of rotation. d, therefore, an earth connectionis afforded from the main line for currents received from a distantstation, either through wire 12 or 14:. hen, as in the position shown inthe drawings, 12 is connected with segment 6, the mainline is connectedto earth through the wire 18, back contact of armature-lever m, wire 12,section 6, wire 9, wire 7, hub b, and wire 10; but upon a half-rotationof the d ynamo-arm ature, however, and when section 6 is in contact withthe brush with which wire 14 is joined the main line is given an earthconnection through wire 20, wire 19, back contact of armature-lever m,wire 14:, section 6 of huh (1, wires 9 and 7, hub 11, and conductor 10.Upon operating key connection between arm ature-leverm and conductor 12will be broken; but in this case at points of the armature rotation anearth connection will be afforded by way of wire 18, the front contactof m, wire 11, hub c, the armatureconductor, hub I), and conductor 10,and at otherpoints of rotation,wlien wire 11 is joined with sections 4and 2, there will be an earth connection through wires 8, '7, and 10.During that part of rotation when wire 11 is in connection with segment3 there will be no connection through hub 0, but one will be afforded,as before, through wire 14: and hub d by way of conductors U, 7, and 10.

In the transmission of messages to a distant station when key 7. isdepressed positive pulses, as those shown in Fig. :3, will be transmittted from the dynamo through section 1 of hub 0, wire 11, frontcontact of armaturelever m, and conductors 1S and 20, while the lengthof the pulses will be somewhat less than a full positive wave, dependingupon the width of sections i and 2 and their surround- By means of hubing insulating material. When section 1 is in contact with conductor 11,the pulse generated is transmitted to line, but when the shortersegments 2 and 4 are brought into contact with wire 11 the line will bedisconnected from the dynamo and placed to earth, thus affording it anopportunity to become discharged. Also, the dynamo, when connected withwire 11, is disconnected from wire 13, so that while 11 is receiving apositive pulse no current will flow over 13. At the next halfrotation,however, section 1 is brought in contact with the brush of wire 13, whena negative pulse generated in the armature will be transmitted into saidbranch 13. Thus, as the armature rotates, 11 and 1 3 are alternatelyconnected with the dynamo and are fed, alternately and respectively,with positive and negative pulses, while the main line at thetermination of each positive and negative pulse is disconnected from thedynamo and is connected to earth to permit its electrical discharge.

The wires 11 and 13, while ready to receive pulses from the dynamo, willnot be fed with full currents except as the armature-levers m and m aredepressed to front contact. If both on and m are depressedat once, thetwo conductors 11 and 13 will receive positive and negative pulses, asabove described. These branches, however, will receive considerablecurrent regardless of the position of levers m m from the fact thatconnections to the main line are effected by way of wires 15 16, theparticular purpose of which will be more fully hereinafter described.

At a receiving-station are employed two relays A 13, each of which isprovided with a permanent horseshoe magnet g, soft iron cores, andelectromagnetic coils h, as shown in Fig. 5. It may be assumed thatrelay A at the distant station is actuated upon the depression of key 70at the transinittlug-station, and B by key 70. The cores and permanentmagnet are so arranged that the positive pulses sent to line upon thedepression of key 7.: shall add to the permanent magnetism of A at thedistant station and shall neutralize or diminish that of I while uponthe depression of key 70 the permanent magnetism of A will be diminishedand that of B increased. By this means, upon the depression of key it,relay A at the receiving-station will attract its armature, while thearmature of B will be attracted upon the depression of key 7.3. Also,upon the simultaneous depression of both It and 7s and the transmissionof successive positive and negative pulses over the main line thearinatures of relays A and B will both be attracted to a signalingposition 5 but it is to be noted that upon the simultaneous transmissionof positive and negative pulses positive pulses will not act upon thepositive relay or negative pulses upon the negative relay, as if onlypositive pulses were being transmitted or only negative pulses, from thefact that a rapid succession of positive and negative pulses through thecoils of an electromagnet will tend to produce a neutral or non-magneticeffect, whereas positive or negative pulses alone will each producestrong magnetic actions. To overcome this difficulty is one of theobjects of my invention, and to this end I have provided arrangementsand means in which auxiliary electromagnets n and the branches 16, withrheostats 7'4", are essential parts, although in case of shorter linesthe branches 15 16 may be omitted.

If positive pulses were received from a distant station only, thearmature of relay A should be attracted, breaking the local circuit,including electromagnet 0, but the local circuit, including magnet n,would remain closed and would still exert a retracting pull upon thearmature of A that is to say, upon the transmission of positive pulsesonly the armature of relay A is in a partially-balanced condition fromthe factthat it is pulled from the one side by magnet 02 and from theother by the cores of relay A. Likewise, if only negative pulses weretransmitted from the distant station, B would attract its armature andbreak the circuit of magnet n, leaving the circuit of magnet 0 closed,and consequently the armature of relay B in a partially-balancedcondition, as above described respecting the armature of A, under the influence of positive pulses alone. Thus upon the transmission of positivepulses for one message or negative pulses for a second transmission thearmatnres of A B will be partially retracted by their retracting-magncts n 0. If, however, both positive and negative pulses, as thoseshown in Fig. 4, are transmitted from a distant station, the armaturesof A and B will both be attracted and the circuits both of 0 and n willbe broken, thereby leaving the armatures subject to the influence of Aand B only. In this case the magnetism of A and B is much weaker than ifthe relays were subject to pulses of one polarity only, but while weakerthey still have a capacity to pull their armatures with a force almostequal to that which they would have if under the influence of pulses ofone polarity only with the retracting-magnets 0 n in action. To stillfurther equalize the actions of relays A B under the influence of pulsesof one polarity or of both, I provide the branches 15 16 with rheostats7" 4". By this means positive and negative currents will at all times betransmitted, although of much less strength than those of normal force.(Shown in Figs. 2, 3, and 4.) By this arrangement pulses from the dynamowill be constantly directed to line, but owing to the resistances r 1-they will be of comparatively small strength. These weakened pulses whenreceived from a distant station will flow through the main-line coils ofA B and produce an effect tending to neutralize the effects of strongercurrents of one polarity. For example, if at the distant station the key7c is depressed strong positive pulses will flow therefrom and throughthe main-line coil of relay A. At the same time, however, owing to thepresence of rheostat r and branch 16 at the distant station, weakenednegative pulses will be transmitted in alternate order, thereby tendingto neutralize in a degree the magnet-ism produced by thestrongerpositive pulses. Thus in relay A not only is the armature undera retractive force from magnet 02, but its magnetism which would beproduced by the strong positive pulses will be considerably reduced bythe weakened nega tive pulses, and by both of these agencies thearmature of A will be under substantially the same tendency to move tofront contact as when strong positive and negative pulses arealternately transmitted.

As shown in Fig. 1, Z represents the ordinary artificial line of adiplex or quadruplex system, while at the left are representedrepeating-.sounders p q and reading-sounders s t, such as arecustomarily employed in quadruplex systems where the main-line relaysclose their local circuits on back contacts. Also, in Fig. 1 are shownbranches including condensers and rheostats around the front contacts ofthe transmitting-sounders, which serve to dissipate sparks arising atsuch points. The branch around the front contact of m includescondensers c and rheostat r", while the branch around the front contactof m includes 0 and r. It may also be noted that the presence ofbranches 15 16, including T 1", respectively, serve a similar purpose.

In Fig. 6 are shown receiving-relays, sounders, and connections, as inFig. 1, except that the electromagnets n 0 act upon armaturesindependent of those which are under the influence of the relay-cores ofA B. This form of relay, although somewhat more complicated inconstruction, I find advantageous in that the armature-lever is subjectto less vibration than when the same armature is under the directinfluence of two opposing magnetic poles.

In Fig.- 7 the transmitting and receiving apparatus of Fig. 1 isreplaced by the bridge form, in which two relays A B are placed in thecross branch of a system consisting of four branches formed of the mainand artificial lines and the two rheostat branches to n, which arejoined at w with transmitters m 'm.

7 What I desire to claim and secure by Letters Patent is 1. In atelegraph system, an alternatingcurrent dynamo at atransmitting-station, two transmitting-keys, a main line, two receivingdevices at the receiving-station, and collector-segments and earthconnections for directing over the main line a series of positive pulsesproduced by said dynamo for transmitting one message, and a series ofnegative pulses produced thereby for transmitting a second message.

2. In a telegraph system, an alternatingcurrent dynamo at thetransmitting-station, a main line, collector-segments through which themain line is normally connected to the erator positive pulses for onemessage and.

negative pulses for the second in combination with two interconnectedretracting-magnets,

one for each relay at the receiving-station, so arranged that the actionof one relay may throw out of action the retracting-magnet of the other,substantially as described.

4,. In a telegraph system in which two messages are transmitted, one bypositive and the other by negative pulses, two mainline relays A, B,responsive to positive andnegat'ive pulses, respectively,retracting-magnets n, 0, and means whereby-magnet nis rendered inactiveby the operation .of relay B, and

magnet 0 by relay A, as and for the purpose described.

5. In a diplex-te'legraph system, two mainline relaysat each station,responsive to positive and negative pulses, respectively, which arenormally subject to weak positive and weak negative pulses and which arebrought into action by strengthened positive or negative pulses,respectively, retracting-magnets n, 0, and means whereby theretractingmagnet 01 of relay A is removed from action by relay B whilethe circuit of magneto is broken by relay A, as and for the purpose setforth.

6. In a telegraph system, an alternatingcurrent dynamo at each stationprovided with earth connections, two transmitters, connections forjoining the poles of said armature alternately with the main line bysaid transmitters, connections for joining the main line to earthimmediately upon its disconnection from the generator, and connectionsfor joining said generator to earth when the transmitters are in theirback positions.

7. In a telegraph system, an alternatingcurrent generator at onestation, two transmitters m m, an armature for said generator whosewindings are connected to a hub, 12, and thence to the earth, a hub 0having sections 1, 2, 3, 4, for effecting alternate connections bothfrom the dynamo tothe front contacts-of the two transmitters and alsofrom the line to earth, and hub cl, having sections 5 and 6 foraffording alternate earth connections from the mainline by way of theback contacts of the two transmitters m m.

8. In a diplex-telegraph system, thecombination of the two transmittersm, m for sending two independent messages to line, analternating-current dynamo, branches 11 and 13 leading to the frontcontacts of said transmitters, and branches '15 and 16 for normallyconnecting branches 11 and 13 with the main line, as and for the purposeset forth.

9. In a telegraph system, the combination of an alternatingcurrentgenerator, two transmitters, branches 11 and 13, leading from saidgenerator to the front contacts of said transmitters, branches 1'5 and16 for permanently connecting conductors 11 and 13 with the main line,receiving instruments at the distant stationconsisting of relays A, B,and retracting-magnets n, 0, whose circuits are closed at back contact,the circuit of 0 including the back contact of relay A, and the circuitof at the back contact of relay B, as and for the purpose set forth.

10. In a telegraph system, the combination of a main line, twotransmitters at one station, two receiving devices at a distant -stationand an'alternating-current generator having an armature a and shaft e, ahuh I) rigidly fixed upon said shaft having connections as set forth, -ahub c placed upon said shaft having sections 1, 2, 3, 4:, for connectingthe dynamoarmature alternately with branches 11 and 13 and forconnecting said branches with earth at intervals between pulses, as andfor the purpose set forth, and hub at having two sections foralternately affording earth connections with the back contacts oftransmitters m, m.

OLIVER R. ROBERSON.

Witnesses:

GERRITT SMITH, JOHN G. SANDERS.

